It has been a goal, in the field of smoking articles, to provide a tobacco substitute which would possess those properties which are most desired in tobacco and which would have none of those properties which are least desired in tobacco.
In attempts to discover or develop a satisfying and pleasant tobacco substitute, numerous materials have been investigated for possible utilization as a substitute for all or part of the tobacco customarily used in smoking products. Some of the materials which have been investigated include, for example, paper pulp, as described in Osborne, U.S. Pat. No. 3,125,098, waste beet pulp, as described in Hind et al., U.S. Pat. No. 3,703,177, carbon or graphite fibers, mat or cloth, as described in Bennett, U.S. Pat. No. 3,738,374, and coffee bean hulls, as described in Deszyck, U.S. Pat. No. 3,796,222. However, time and experience have shown that discovery or development of a fully satisfactory, economically feasible tobacco substitute has been an elusive, and yet to be attained, objective. The subtleties of smoking and the intricate nature of producing a product which will be pleasing to the discerning smoker, from viewpoints of taste, flavor, aroma and other aspects of tobacco desired by such an individual, make discovery or development of a satisfactory tobacco substitute extremely difficult. Hence, while numerous attempts have been made to prepare a tobacco substitute, including many attempts made during wartime and inflationary periods when obtaining tobacco was difficult and expensive, none has resulted in the discovery or development of a fully satisfactory product.
Of the many materials investigated for use as tobacco substitutes, carbohydrates of naturally occurring origin, such as sugars, starches and celluloses, have been tried because of their ready availability, good burning characteristics, and low cost. For example, such materials are described in Osborne, U.S. Pat. No. 3,125,098; Hind et al., U.S. Pat. No. 3,529,602; and Bennett, U.S. Pat. No. 3,738,374. However, the carbohydrates tested in smoking articles have generally been found to provide a smoke which is not as pleasant as that of tobacco, having a taste which is harsher and more pungent that that of most tobaccos. This undesirable feature has been particularly associated with the sidestream smoke which occurs between puffs and the smoking article. Certain carbohydrate materials have also been found to be difficult or impossible to use as tobacco substitutes or as wrapper materials due to their inability to survive the required handling and shaping called for in the fabrication process. In order to be used as a wrapper in a smoking article, it has generally been necessary for a smoking material to be capable of being processed into a uniform, paper-like sheet without having any hard, splinty areas, and to have adequate resiliency and strength to enable its wrinkle-free application to smoking articles in such a manner that it will not tear due to vigorous digital or oral manipulation. In order for materials to be used as filler in a smoking article, it has generally been necessary for them to possess the capability of being shaped into elongated ribbon or shred-like forms having sufficient strength to withstand handling without breaking down into fine particles or dust.
Attempts have been made to convert carbohydrate materials of the type described above to more desirable forms. For example, a tobacco substitute material has been prepared by heating wood to high temperatures in the absence of air to convert the wood to a charcoal, which may then be combined with flavoring materials to produce a smoking product, as is set forth in Siegel, U.S. Pat. No. 2,907,686. In another process, a tobacco replacement material has been prepared by the catalytic degradation of carbohydrate materials at temperatures between 100.degree. and 250.degree. C., as is set forth in Morman et al., U.S. Pat. No. 3,545,448. In still another process, a smoking material is formed by the thermal reaction of a cellulosic material in the form of a fibrous carbohydrate at a temperature of about 275.degree. to 375.degree. C. in a non-oxidizing atmosphere, as is set forth in Briskin, U.S. Pat. No. 3,861,401. In still another process, a smoking product is prepared by oxidizing cellulose and adding certain mineral ingredients to the same, as is set forth in Briskin, U.S. Pat. No. 3,447,539. However, none of these processes has resulted in a product which is completely satisfactory.